With the rapid development of multimedia applications, and the fact that a large quantity of multimedia data is distributed via the internet network, the protection of video becomes a major problem. It is therefore necessary to protect them. This can be done using video watermarking methods. To be really efficient, the mark has to be resistant to malicious attacks. Methods developed for still images cannot be efficiently used for video. Effectively, if a mark is embedded in only one image of the video, a temporal filtering along the motion displacement can easily removed it without significant degradation of the video. It is therefore necessary to define specific techniques for video. In this context, we present in this paper a video watermarking method based on the use of video mosaicing. We show that the proposed method is resistant to temporal filtering attack.